Where’s All the Ocean Trash?

The Great Pacific Garbage Patch. We’ve all heard about it. Some people say its twice the size of Texas. Others peg it at bigger than the continental United States. Yet, scientists can’t seem to find most of it.

Back in the 1970s, the National Academy of Sciences put the number of plastic reaching the oceans at 45,000 tons a year. Since then, plastic production has increased by 5 times.

Millions of tons of plastic make its way into the oceans every year. But, 99% of it can’t be found.

These patches of trash and plastic are often hard to spot. They can’t be seen from space or the air. Even observers aboard ships have a hard time spotting the trash. The easiest way to find it is to collect samples with nets. That’s what Professor Adres Cozar of the University of Cadiz and his colleagues attempted to do in 2010’s Malaspina Expedition.

The expedition, funded by the Spanish National Research Council, came up surprisingly light. The expedition, which included two ships, travelled 33,000 nautical miles and collected 3,000 samples from more than 140 sites. Their findings were published in the Proceedings of the National Academy of Sciences. The scientists calculate the oceans have between 7,000 and 35,000 tons of floating plastic. That’s a ton. But, nowhere near the millions of tons expected.

So, where is it all at? Scientists have several ideas about the missing plastic. One idea suggests marine plants and animals are affecting the plastics. Whether by eating it, or by anchoring themselves to it and weighing it down into the deep ocean. Marine life eating the plastics presents a problem since a lot of marine life is in our food chain.

Another theory points to marine bacteria breaking smaller pieces of plastic into extremely small pieces.

“The plastic pollution in surface waters can more easily interact with the ocean life, because the surface layer of the ocean hosts most of the marine organisms,” Cozar said.

Another idea suggested by the authors of the research says some of the plastic could be washing ashore. They don’t put much stock in that theory, though.

The biggest issue would be if fish are eating the plastics. More research needs to be done on the effect plastics would have on fish that we eat.